Avalanche Forecast

Issued: Mar 30th, 2024 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet and Persistent Slabs.

Avalanche Canada wlewis, Avalanche Canada

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While the best riding conditions may be found on north facing, alpine slopes - persistent weak layers may still be reactive here.

Watch for changing surface conditions on sunny slopes.

Summary

Confidence

Moderate

Avalanche Summary

The last reported avalanche was a close call size 1 rider triggered slab on Thursday (photo below). While the slab was only 10 cm deep, this shows the potential of small avalanches in steep or unsupported terrain features.

While there has been minimal avalanche activity over the past week, professionals in the region are still weary of the persistent slab problem. Warm temperatures may increase the reactivity of this problem, and will produce wet avalanche activity.

Snowpack Summary

Up to 10 cm of recent snow can be found over a widespread crust. Surface snow is expected to become moist or wet with rising temperatures and sun, on steep south facing slopes the crust below may also break down.

The facet/crust layer that produced large avalanches during early March is buried 80-150 cm deep. While no recent avalanche activity has been observed on this layer, it continues to produce concerning snowpack test results. It has become a low-probability, high-consequence problem on north-facing slopes above 2000 m. It is uncertain how this layer will react to rising temperatures.

Weather Summary

Saturday Night

Partly cloudy. 20-40 km/h northerly ridgetop wind. Freezing level drops to 700 m.

Sunday

Sunny. 20-40 km/h northwest ridgetop wind. Freezing level rises to 2800 m in the afternoon, bringing treeline temperatures to +9 °C.

Monday

Freezing levels remain above 2500 m overnight and throughout Monday. Sunny. 20-30 km/h west ridgetop wind. Treeline temperatures near +8 °C.

Tuesday

Freezing levels remain above 2000 m overnight and throughout Tuesday. Cloudy. 40 km/h southwest ridgetop wind. Treeline temperatures near +2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Problems

Loose Wet

An icon showing Loose Wet

Potential for wet avalanche activity (slab and loose) increases as temperatures rise, but concern is greatest on steep, sun affected slopes. Avalanches may initiate easily on the smooth crust below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs

Concern remains for human-triggering a persistent weak layer on sheltered north aspects above 2000 m. If triggered, avalanches will be large and destructive. Avoid shallow snowpack areas where triggering is more likely.

Aspects: North, North East, North West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 31st, 2024 4:00PM

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